empedocles affirms, that heat and cold give the difference in the generation of males and females. hence is it, as histories acquaint us, that the first men originated from the earth in the eastern and southern parts, and the first females in the northern parts. parmenides is of opinion perfectly contrariant. he affirms that men first sprouted out of the northern earth, for their bodies are more dense; women out of the southern, for theirs are more rare and fine. hippo, that the more compacted and strong sperm, and the more fluid and weak, discriminate the sexes. anaxagoras and parmenides, that the seed of the man is naturally cast from his right side into the right side of the womb, or from the left side of the man into the left side of the womb; there is an alteration in this course of nature when females are generated. cleophanes, whom aristotle makes mention of, assigns the generation of men to the right testicle, of women to the left. leucippus gives the reason of it to the alteration or diversity of parts, according to which the man hath a yard, the female the matrix; as to any other reason he is silent. democritus, that the parts common to both sexes are engendered indifferently; but the peculiar parts by the one that is more powerful. hippo, that if the spermatic faculty be more effectual, the male, if the nutritive aliment, the female is generated.